Medical science further owes to him the classification of new growths on a natural histological basis, the elucidation of leucaemia, glioma and lardaceous tumours, and detailed investigations into many diseases - tuberculosis, pyaemia, diphtheria, leprosy, typhus, &c. Among the books he published on pathological and medical subjects may be mentioned Vorlesungen fiber Pathologic, the first volume of which was the Cellular-pathologic (1858), and the remaining three Die Krankhaften Geschwiilste (1863-67); Handbuch der speziellen Pathologic and Therapie (3 vols., 1854-62), in collaboration with other German surgeons; Gesammelte Abhandlungen zur wissenschaftlichen Medizin (1856); Vier Reden fiber Leben and Kranksein (1862); Untersuchungen fiber die Entwicklung des Schlidelgrundes (1857); Lehre von den Trichinen (1865); Ueber den Hunger-typhus (1868); and Gesammelte Abhandlungen aus dem Gebiete der afentlichen Medizin and der Seuchenlehre (1879).

Of his writings on social and political questions may be mentioned Die Erziehung des Weibes (1865); Ueber die nationals Entwicklung and Bedeutung der Naturwissenschaften (1865); Die Aufgaben der Naturwissenschaften in dem neuen nationalen Leben Deutschlands (1871); Die Freiheit der Wissenschaft im modernen Staat (1877), in which he opposed the idea of l - L eckel - that the principles of evolution should be taught in elementary schools - on the ground that they were not as yet proved, and that it was mischievous to teach a hypothesis which still remained in the speculative stage.